A few weeks ago I lost my 21 year old AFC. I changed his water and an hour later he was lying on his back dead. I figured he would someday die of old age, but this happened directly after I changed his water. I have always used tap water for his water changes with no problems. After 20 years I figured he could handle it.

Later I found that a friend of mine lost all his fish around the same time. It turns out that last month my city started adding chloramine (instead of chlorine) to the water supply, and after some googling it appears to be deadly to fish, amphibians and reptiles. It's apparantly a new trend in water treatment, in spite of many controversies. It takes special steps to remove chloramine, it's not easy like chlorine. It won't evaporate if you let it stand. If you dechlorinate chloramine, you are left with ammonia, so you have to deal with that too. What a huge pain!

The lesson here is that tap water is not stable. You can use it for years with no problems and then they change their treatment chemicals and your pet is dead. I'm very angry about this, I had this guy my whole adult life.